Security screenings can be conducted of persons upon entry into certain infrastructures, for example the departure area of airports, or buildings with increased security requirements (for example, courts, prisons, diamond mines, etc.), or for major events (for example, concerts, sports events, etc.). In the process, persons pass through a transition area (often referred to as a checkpoint or control point), at which the persons, and possibly hand-held items if present, are screened, for example, for hazardous or prohibited objects or substances that are worn concealed under the clothing, or concealed in the body.
Control points at airports can have so-called walk-through metal detectors, for example, which are designed in a manner similar to a free-standing door frame, into which highly sensitive metal detectors are integrated in order to detect metallic objects, such as weapons, carried in concealment on the body of a person to be screened, and to trigger an appropriate alarm. When an alarm is triggered, the person in question is subjected to a follow-up screening by security personnel, for example by means of a hand-held metal detector and/or manual scanning.
These control points represent a bottleneck with regard to throughput of persons, since follow-up screenings always require more time than automatic screenings via the walk-through metal detector.
Personal scanners can be used at such control points which scan the bodily surface of a person by means of electromagnetic radiation, the radiation penetrating essentially the clothing but not the person him/herself, and being reflected on the skin of the person. Based on the backscattered radiation, so-called backscatter images of the person may be generated, in which objects or substances that are worn concealed under the clothing may be identified.
To ensure the necessary probability of detection, the responsible certification bodies for such devices have required that the sensor data generated by a screened person be automatically evaluated, and that bodily areas possibly subject to a follow-up screening be indicated to security personnel as an alarm notification.
In order to decouple the throughput rate at the control point from the time requirements for the follow-up screening, follow-up screenings may be conducted at a second location by security personnel present there.
To protect the privacy rights of persons to be screened, detection results are recorded in anonymized form. Even for the above-mentioned backscatter scanners or millimeter wave scanners, there is no generation of realistic full-body images of a screened person by which the person could be identified. Instead, the bodily areas to be subjected to a follow-up screening are marked on standardized graphical representations (so-called avatars). Only information concerning the bodily areas to be subjected to a follow-up screening is obtainable from the avatar. Thus, it is possible, for example, for the person who is to undergo a follow-up screening to inadvertently exchange places in the waiting line on the way to the follow-up screening point. It is not possible for the security personnel at the follow-up screening point to unequivocally associate the graphical information, displayed there on a display device, with a specific person in the line. This may represent a potential security gap, which in the prior art is avoided by use of additional supervisory personnel in order to avoid waiting lines.
Some systems for controlling the movement of at least one person, who is screened at a control point, to a follow-up screening point comprise an X-ray screening system at the control point, having an entry area defined by walls and an entrance gate, and an exit area defined by walls and an exit gate. The gates are automatically controlled, based on a screening result at the control point, so that a person who has been screened and found to be safe is allowed to leave the screening area. Further gates and walls define an additional holding area for persons to be subjected to a follow-up screening, the holding area being designed so that persons who are to undergo a follow-up screening are individually led to the follow-up screening point. The above-described problem is avoided by the controlled separation of the persons who are to undergo a follow-up screening. However, the known system may have an adverse impact on the throughput at the control point, since as soon as the receiving capacity of the follow-up screening point is reached, the first control point is also blocked, resulting in delays. In addition, the holding area with walls and gates is unpleasant for passengers, who may possibly already be under stress, in particular when persons traveling together are separated thereby from fellow travelers.
Other systems can include acquiring a biometric profile for a person, for example a 3D model of the person or data for recognizing the face of the person, for contactless identification and tracking of the person in an area such as a stadium. For example, the biometric profile of authorized persons may be detected at the entrance to the stadium, so that unauthorized persons in the stadium may be identified due to the fact that no biometric profile for this person has been detected.